Jasper Cillessen, the goalkeeper lined up to replace David de Gea at Manchester United, could become cup-tied in the Champions League if he overcomes a calf injury to play for Ajax in their qualifying round tie against Rapid Vienna tonight.

Jasper Cillessen, the goalkeeper lined up to replace David de Gea at Manchester United, could become cup-tied in the Champions League if he overcomes a calf injury to play for Ajax in their qualifying round tie against Rapid Vienna tonight.

United are understood to have struck an agreement with Ajax and Cillessen that will see the Holland No 1 move to Old Trafford in the event of De Gea leaving for Real Madrid.

Cillessen is battling what is described as a 'slight' calf injury ahead of the game in Vienna, but if he plays, he will become ineligible for the Champions League group stages if Ajax progress to that stage of the competition.

Should Ajax exit during the qualifiers, however, Cillessen would then be free to play in the group stages for United.

Due to concerns over Cillessen's injury, Ajax coach Frank de Boer has named third-choice goalkeeper Andre Onana in his squad for the first-leg in Austria, with No 2 'keeper Diederik Boer on stand-by to play.

Cillessen, 26, has emerged as Louis van Gaal's preferred option to replace De Gea, either in this transfer window or next summer, depending on when the Spain goalkeeper leaves for Real.

Having worked with Cillessen as Holland manager, Van Gaal and goalkeeping coach Frans Hoek believe Cillessen's potential and, in particular, his footwork and ability on the ball, place him ahead of Tottenham's Hugo Lloris.